The concept of autonomous aircraft ground travel and taxi without use of the aircraft's main engines or tow vehicles has received much attention lately. Systems designated as “electric taxi” systems to move aircraft during taxi after landing and before takeoff have been proposed by Applicants and others. Such systems are described, for example, in commonly owned U.S. Pat. Nos. 7,975,960 and 8,220,740 to Cox et al and in U.S. Pat. No. 7,445,178 to McCoskey et al, as well as in U.S. Patent Publication Nos. US2011/0089289 to Wilson and US2012/0104158 to Charles et al. Such systems typically suggest the use of one or more electric motors mounted in connection with aircraft main or nose landing gear wheels to drive the wheels and move the aircraft during taxi without requiring operation of the aircraft's main engines or a tow tractor, tug, or other tow vehicle. Implementing this concept, however, has been accompanied by challenges.
One challenge has been to provide a cockpit control system that is easily accessed and used by the aircraft's pilot and cockpit crew to operate an electric taxi system effectively, both alone and in conjunction with the aircraft's engines, to guide the aircraft as required during ground movement. Currently, aircraft are powered during taxi by thrust from the aircraft's engines, which requires the pilot or crew to adjust engine thrust, steer the aircraft, and apply the aircraft's brakes as needed while keeping the surrounding ground environment in view to ensure that the aircraft is traveling along a clear path. An electric taxi system adds a different level of control for which the pilot and crew must be responsible. The presently proposed electric taxi systems require constant pilot hand input and do not provide as much information as is desirable to enable the pilot to follow taxi instructions or move the aircraft during taxi as efficiently as possible. A cockpit system that provides a substantially “hands free” option to guide an aircraft that is not equipped with an electric taxi system during taxi at an airport with a plurality of taxi paths is described in U.S. Pat. No. 8,280,618 to Feyereisen et al. The “hands free” option is accomplished by providing an audio input from the pilot or crew as part of the aircraft's avionics system. It is not suggested whether, or how, this system could be adapted or used to provide the control necessary for an aircraft with an electric or like taxi system that drives the aircraft autonomously during taxi, either alone or in conjunction with operation of the aircraft's engines.
A need exists, therefore, for a cockpit control system and method specifically designed for an aircraft equipped with an engine-free electric taxi system to power ground movement that provides and facilitates optimum control over aircraft ground travel by an aircraft's pilot and cockpit crew and can be operated with minimal mechanical or other input from the pilot and/or crew to achieve a substantially hands free control of aircraft ground travel.